The relationship between anxiety and smoking in high-risk subgroups, such as patients with Post-traumatic Stress Disorder (PTSD), has received little empirical attention. Preliminary research indicates that 60% of PTSD combat veterans smoke, and that during a laboratory stressor, PTSD patients report greater smoking withdrawal symptoms in response to trauma- related Stroop cards. These results suggest that trauma-related material may serve as a cue for smoking in PTSD combat veterans. The first purpose of this proposal is to determine whether increased craving for cigarettes after Vietnam words occurs in veterans with PTSD as compared to veterans without PTSD or GAD patients, and whether PTSD patient groups experience greater relief from their symptoms, including PTSD reexperiencing and hyper-arousal symptoms after smoking. A well-established script-driven imagery procedure will be utilized to examine the effect of different scripts (disorder-related, general stress, neutral) across study groups, and the effect of nicotine on symptom reduction. The second purpose of this proposal is to explore the link between anxiety and smoking in the natural environment by comparing study groups. Subjects will monitor their smoking using an ambulatory heart rate monitor and diary. Besides potentially confirming parallel laboratory and real-world data on a relationship between anxiety and smoking, a naturalistic observation study will allow examination of whether the association between smoking and anxiety is due to other circumstances which co-occur with both anxiety and smoking. The ultimate goal of this research is to identify risk factors in subgroups of smokers who are at risk for increased smoking and difficulty in smoking cessation that could lead to important prevention and intervention efforts.